package com.itheima.reggie.filter;


import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.BaseContext;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 检查用户是否已经完成登录
 */

@WebFilter(filterName = "LoginCheckFilter", urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {

    //进行路径比较,支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        //获取本次请求的URI
        String requestURI = request.getRequestURI();
        log.info("本次请求路径{}",requestURI);
        //判断本次请求是否需要放行,这些都不需要被拦截
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",
                "/user/sendMsg",
                "/user/login"
        };
        //判断本次请求是否需要处理
        boolean check = check(urls, requestURI);
        //如果不需要处理,直接放行
        if (check) {
            log.info("本次请求不需要处理{}",requestURI);
            filterChain.doFilter(request, response);
            return;
        }
        //需要处理,如果已经登录,则直接放行
        Object attribute = request.getSession().getAttribute("employee");
        if (attribute != null) {
            //把id设置到当前线程中去
            Long empId = (Long) attribute;
            BaseContext.setCurrentId(empId);
            //不为空,已经登陆,放行
            log.info("用户已经登陆{},用户id为{}",requestURI,attribute);
            filterChain.doFilter(request, response);
            return;
        }


        //需要处理,如果已经登录,则直接放行
        Object userAttribute = request.getSession().getAttribute("user");
        if (userAttribute != null) {
//            //把id设置到当前线程中去
            Long userId = (Long) userAttribute;
            BaseContext.setCurrentId(userId);
//            //不为空,已经登陆,放行
            log.info("用户已经登陆{},用户id为{}",requestURI,userAttribute);
            filterChain.doFilter(request, response);
            return;
        }
        log.info("用户未登录{}",requestURI);
        //session为空,说明没有登录,返回结果,通过输出流方式,想客户端页面响应数据
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;

    }

    /**
     * 路径匹配,检查本次请求是否需要放行
     *
     * @param requestURI
     * @param urls
     * @return
     */
    public boolean check(String[] urls, String requestURI) {
        for (String url : urls) {
            //返回true表示匹配上了
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match) {
                return true;
            }
        }
        return false;
    }
}
